JAW's 150Y: Stanza Struts into 120Y

Enter one 1980 Stanza, delivered, no engine, $50. This is what one looks
like after all the goodies have been stripped. Oh and yes, the drivers side
radius rod was slightly bent from some accident, but it straighened out
okay. Nothing else looked bent however, well, as far as I could tell...

Straight away bolted the 13" front wheels onto the 120Y, couple of
months later put the front seats in. The diff was way too different, and it
was drum anyway, so I ditched that. The struts stayed in the shed, waiting,
until now...

Stanza strut on left, 120Y strut on right.

Day 1

Lets get down to the facts. Haven't seen any serious techo doco on it,
but saw in a Street Machine ages ago that "Stanza struts bolt up to 120Ys
for bigger brakes and tougher suspension", and Martin Pott has a couple of
guys saying this and that, but can it really be done?

Firstly armed with tape measure and verniers, got me this basic set of
data together (some measurements a bit approximate):

Item

120Y

Stanza

Lower control arm length, from centre of lower ball joint to centre
of pivot bolt

From the measurements things look okay. Same length, beefier springs,
tougher shock and bigger brakes. The control arm slightly longer, but a
little bit more negative camber shouldn't be too bad(?)

Problem 1
The 120Y brake has a steel pipe from the caliper which connects to
the flexible hose half way up the strut. The Stanza has the
flexible hose straight from the caliper. Hence you can't just join
the brakes up (even though it is the same connectors).

Problem 2
The top of the strut tower is different to the 120Y. The Stanza
requires a 92mm hole, whereas the 120Y body has only a 80mm
hole.

Potential solutions:

The brake hose connector on the inner guard can be moved to a place
closer to the caliper (as was on the Stanza) allowing the free full
travel of suspension.

A small male to male connect could join the 2 flexible hoses together
- the one from the Stanza caliper to the one on the 120Y body - making
sure to tie them off so as not to interfere with suspension and steering
travel.

Enlarge the hole at the top of the strut tower...

Sadly the top of the 120Y strut cannot be swapped onto the Stanza struts
because the tread on the top of the shock is bigger and the offset of the
strut top would raise the car 30mm higher - bad.

The radius/castor rods

Well the stanza ones are longer which would put the castor waaay out.
The 120Y ones would make a good fit *except*:

The bolt holes on the connection to the control rod are smaller.

The bolt holes on the connection to the control rod are in different
places.

The Stanza has a cut out between the holes allowing one of the ball
joint bolts to fit in place - that 120Y ball joint bolt is smaller
meaning no cutout required.

I think the easiest way here is going to be to machine 30mm down the
Stanza rod, doesn't need to be threaded because the bolt never goes that
far down. I might check and see if a 180B or 200B or other Niss/Dat car
might happen to have a radius rod that would do the trick.

Tie rods
and sway bar

The tie rod end ball joints are exactly the same, and the little bit
extra length that will be required I'd say is available. If not, I have the
rest of the Stanza steering bits, can swap the threaded rods over.

The sway bar on the 120Y (amazingly enough) is fatter, and sits still in
the perfect place. The little mounting towers should take care of any
slight misalignment

That was all for Day 1. A bit more thought and some discussions with
others is in order - to continue or not to continue. Bottom line so far:
Looks like a feasible swap, but it isn't just a bolt in operation. And at
the end of the day, who knows what the steering geometery is going to be
like. Only one way to find out...

Day 2

Stanza radius rod end.

Well I decided to persist. I got my mate Howard 'duck' Jones to machine
30mm off theradius rods. looks like this. Top man, top job. It's about the
only thing that I couldn't do myself, but I sure would love a lathe to give
it a try...

120Y radius rod end. Note how there is no 'cut out'
that gets the stanza end around one of the ball joint bolts.

Meantime I've got the jigsaw out, load the metal blade and taken to the
top of the shock tower. Took out just enough metal to allow the struts to
pop through the top. Pretty easy to do. Note that for some stupid reason
the 3 bolts that go through the shock tower were 1mm further spread out
than on the 120Y. Opened the holes up that 1mm, and through they came.

Day 3

It was a cold and rainy night, so not much further activity. Good news,
the radius rods fitted great - note I can now confirm that the
machined 30mm section does not need to be threaded

Footnote: it's really annoying winding a nylon nut down that extra inch
and a bit...

Strut number 1 in firmly in place, I used the 120Y sway bar stand-offs
rather than the stanza ones even though they were the same length. The
rationale behind this is that the rubbers were slightly bigger, and the
sway bar is bigger so it stands to reason that the 120Y ones are
tougher.

The tie rod ends bots straight up as expected, no suprises there. Some
eyeballing will be needed to get the toe-in right as the control arms are
that 10mm longer.

Day 4

Cold and rainy again, spent about an hour and a half getting the other
strut on. She's now back on all fours, and... no suprises whatsoever.

She's toed right out as expected due to the overall 20mm distance
increase from the 10mm longer control arms. She's riding high, again as
expected because an A15 in a 120Y body is lighter than a Stanza.

However I was expecting the camber to be 0° or even a little bit
negative, but in fact it was positive. I'll leave the springs for a week or
so to settle, but invariably I'm gonna have to drop the front down a bit.
I'm thinking of cutting 2 coils offa the spring. That way the camber will
become less positive as the ride height reaches a more sociably accepted
level ;)

First benefit found: wow, the shocks work and the front is tough! It's
not gonna rattle me fillings out, but I can tell that the suspension is
going to be much less sloppy that it was before.

All that is left now is to relocate the brake lines. I have a choice or
2 here, I'll let you know which path I take...

Day 5

It's all over. I decided to relocate the brakes lines, as seen in the
piccys. No real dramas there, the steel pipes bend okay in yer hand - you
can see the 'cooling tower' drivers side pipe in the photo where it does a
bit of a spiral into it's new position. Oh well.

The flexible hose chassis mount point was cut off the old strut (it had
2 rivets holing it on) and the position was chosen making sure you could
fully turn left, fully turn right, and placed high so that when the
suspension travels it will have clearance. I'll be sure and update this
page if for any reason I discover that was a *bad* place to put it...

The toe-out I adjusted by eye, I think I still have a little too much
toe-in (overcompensated).

Now for the good news:

After the maiden voyage, the ride height settled down to
ever-so-slightly negative camber, and I'd say she's sitting at most 10mm
heigher than original.

The shocks work nicely, and I can now drive over speed bumps...

The springs are definately stiffer, not quite enough to rattle the
fillings out, but enough to give a bit of a 'noddy' drive down the street
over the little lumps and bumps.

Although my master cylinder is still a bit shot, the 100kph heavy
brake revealed that the bigger disks feel like she pulled up
quicker.

The brake pedal travel is not noticably different - perhaps the
calliper piston bore isn't much bigger, so all is well there.